Quit worring about what's towed to make up milage. I've done all kinds of crazy trailers over the years, but realized nothing will compensate for the versatility of a standard 20' car trailer. A small single axle trailer would hold my 5 and probably tow ok, but I pack way different amounts of tools, spares etc.. depending on the destination....and what if I want to take the 8, not the 5? I often find myself helping out someone that's broke down or bringing home stuff assorted oddball stuff. Beats having several specialty trailers all over the yard for each thing you tow. Make up the difference on the other end, a diesel gave me 7(Detroit) to 9 (Cummins) more MPG with the exact same load. And the Cummins gets 19-20 as a DD

I guess if you have a specific little lightweight 4x4 that is loaded exactly the same, with all the same equipment each time you go somewhere, to do the same exact type of course, then maybe it would justify the .7 to 1 MPG you'll pick up towing it with a 1/2 ton or less SUV or "truck"

A classic example of missing the point. Not everyone wants to spend $40k+ plus to 'save' money at the pump. Or wants to DD a 3/4 ton. And down here where I live, you don't get 20mpg driving a diesel 3/4 ton. And as detailed in the other thread, I know I've got 10mpg in my V10 while my buddies cummins got 14. That'd save me $250 a year in towing (again, for a $6000+ option)....

The average person in this hobby seems to think bigger is better. And that works fine for most. Some people like to think outside the box. To each his own.

The world seems to survive just fine with 4000lb boat trailers on a single axle.